646531564 has 24 divisors (see below), whose sum is σ = 1349284608. Its totient is φ = 265037520.

The previous prime is 646531549. The next prime is 646531591. The reversal of 646531564 is 465135646.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 501322 + ... + 502609.

It is an arithmetic number, because the mean of its divisors is an integer number (56220192).

Almost surely, 2^646531564 is an apocalyptic number.

It is an amenable number.

646531564 is an abundant number, since it is smaller than the sum of its proper divisors (702753044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646531564 is a wasteful number, since it uses less digits than its factorization.

646531564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1003965 (or 1003963 counting only the distinct ones).

The product of its digits is 259200, while the sum is 40.

The square root of 646531564 is about 25426.9849569311. The cubic root of 646531564 is about 864.6955900348.

The spelling of 646531564 in words is "six hundred forty-six million, five hundred thirty-one thousand, five hundred sixty-four".